activity vs trigger point

activity

noun
  • Something done as an action or a movement. 

  • The lexical aspect (aktionsart) of verbs or predicates that change over time and have no natural end point. 

  • Something done for pleasure or entertainment, especially one involving movement or an excursion. 

  • The state or quality of being active; activeness. 

  • The number of radioactive decays per unit time. Unit for it: becquerel or curie 

  • The propery of substances to react with other substances 

trigger point

noun
  • An event, arrangement, provocation, etc. that leads a certain, generally violent or angered, action to be taken. 

  • A hyperirritable spot in the skeletal muscle; a point in tender muscle that tends to elicit pain upon pressure or touch. ᵂᵖ 

How often have the words activity and trigger point occurred in a corpus of books? (source: Google Ngram Viewer )